Crystal structure of the human LRH-1 DBD-DNA complex reveals Ftz-F1 domain positioning is required for receptor activity.

Published

Journal Article

The DNA-binding and ligand-binding functions of nuclear receptors are localized to independent domains separated by a flexible hinge. The DNA-binding domain (DBD) of the human liver receptor homologue-1 (hLRH-1), which controls genes central to development and metabolic homeostasis, interacts with monomeric DNA response elements and contains an Ftz-F1 motif that is unique to the NR5A nuclear receptor subfamily. Here, we present the 2.2A resolution crystal structure of the hLRH-1 DBD in complex with duplex DNA, and elucidate the sequence-specific DNA contacts essential for the ability of LRH-1 to bind to DNA as a monomer. We show that the unique Ftz-F1 domain folds into a novel helix that packs against the DBD but does not contact DNA. Mutations expected to disrupt the positioning of the Ftz-F1 helix do not eliminate DNA binding but reduce the transcriptional activity of full-length LRH-1 significantly. Moreover, we find that altering the Ftz-F1 helix positioning eliminates the enhancement of LRH-1-mediated transcription by the coactivator GRIP1, an action that is associated primarily with the distantly located ligand-binding domain (LBD). Taken together, these results indicate that subtle structural changes in a nuclear receptor DBD can exert long-range functional effects on the LBD of a receptor, and significantly impact transcriptional regulation.

Full Text

Duke Authors

Cited Authors

  • Solomon, IH; Hager, JM; Safi, R; McDonnell, DP; Redinbo, MR; Ortlund, EA

Published Date

  • December 16, 2005

Published In

Volume / Issue

  • 354 / 5

Start / End Page

  • 1091 - 1102

PubMed ID

  • 16289203

Pubmed Central ID

  • 16289203

International Standard Serial Number (ISSN)

  • 0022-2836

Digital Object Identifier (DOI)

  • 10.1016/j.jmb.2005.10.009

Language

  • eng

Conference Location

  • England